There's no dynamic sorting yet. This would have to be done in Node.js.
So you run a DQL query against an NSF, get back a resultset of 20.000 documents that you fetch via 100 requests with each 200 entries between Node.js and Domino, store everything in main memory of the Node.js process and sort it. Next you compute which of these documents fit into the page requested by the browser, return them and throw away the remaining data.
Raise your hand in the beta forum if you think there are better ways to do this :-).